Gross lending came in at £353m last year, down from £834m in 2018, annual results showed.
The lender said it had taken a “conscious decision” to reduce new lending and focus on existing borrowers to protect the average rate the society paid its savers.
Around 70 per cent of existing borrowers were retained.
The results come against a fiercely competitive market backdrop, with a number of lenders revealing an erosion of margins last year.
The Nottingham revealed it will price lending more competitively in the future, as it carries out work to “develop the capability to individually prices each member’s mortgage, based on their own distinct characteristics”.
The society also said it had an “increasing conviction that no member should remain on our SVR for any meaningful period of time at the end of their product term”.
Mortgage advice through the whole-of-market advice arm Nottingham Mortgage Services was delivered to 15 per cent more borrowers in 2019 from the year earlier, but the group did not release exact numbers.
The lender also celebrated its Mortgage Broker Portal going live in November, which is part of a wider focus on digital capabilities
Overall underlying pre-tax profit came in at £10m and membership grew by 20,000, but the lender reported a technical loss after tax of £7.2m.
David Marlow, chief executive, said: “As we entered 2019 we were aware of a number of market and societal challenges that lay ahead…
“Our planned reduction in new mortgage lending, in the face of falling market mortgage yields, was expertly managed to find what we felt was the right balance between the conflicting needs of our mortgage and savings members.
“We set ourselves a target to achieve 70 per cent retention of existing borrowers choosing to stay with us when they get to the end of their promotional period, which was achieved.
“We also launched a number of exciting products, based on broker feedback including retirement interest only and cashback mortgages, which paid out over £75k in cashback to homeowners last year alone.”